Bay 12 Games Forum

Oh, thought of another one:

Will civilizations ever own artifacts? I know bloodlines can, but I mean like governments/institutions controlling art; the Mona Lisa in the Louvre, for example. On that note, will we ever have procedural flags, anthems, or dances that are unique to/associated with a civilization? Can you play someone the song of your people? I could imagine playing a national anthem for people that are currently at war with that nation would probably result in a bar fight.

Upon examination, the fact that water in this game uses averaging between two random tiles makes the flowing water make SOOOO much more sense! It's why pools take forever to drain; they literally can't flow faster than 3 or 4 units per tick into an open square, then the square after that has to half again, and again. The speed of water calculations only masks the fact that the flow rate is abysmally slow; you can really see how slow it moves when you stretch it out over a lot of tiles - or even comes to a near-complete stop. Given that it seems to consider open air and a 1/7 tile of water as equally promising, you can very quickly see a 'blobbing' effect to water in the game.


So aside from good ol' water, there's a few sets of special circumstances that affect water in the game:

• Brooks, flowing water which can be walked over.
• Murky water, which arises from a 'Murky pool' ground tile.
• Salt water, from oceans, seems to have a similar concept.

Turns out brooks are more of a workaround; a 'Brook' is actually a special floor tile that you can walk over, but still allows liquid to pass, like a floodgate. When testing Brooks, I found that the water inside was regular water, not special in any way. Channels containing it we impassable by dwarves, unlike the brook; they had to walk onto the 'Brook' tiles to get to an area I sectioned off via channeling. Not much to say here, since Brooks are more of a cheat way of making water streams you can walk across. The water is ordinary.

Murky and Salt water are far more interesting.

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Murky status for water persists, even when it flows onto regular tiles again. If drained, any water that arises to fill the pool is also murky. Seems to imply water-containing tiles can inherit properties from other tiles, and spread them as they flow. All the better for a liquid body system~

'Murky' is considered a contaminant, and can be removed with a screw pump (this process is probably just deleting the murky water and spawning regular water at the end of the pump).

When regular water from the brook attempted to average between Murky and regular water, it left both tiles as regular, deleting the contaminant. However, dumping fresh water from a bucket into stagnant water does not produce this effect, it remains stagnant. Speaking of buckets; Buckets maintain their contamination status when they are dumped. Stagnant water stays stagnant, fresh water stays fresh.

When fresh water is dumped into a hole, then allowed to mix with murky water, all of the water turns fresh - effectively purifying it. It likely does this to avoid polluting an entire river.

At this point I'd like to note that if Fluid Bodies were used, you could measure contamination levels within an entire body and avoid this problem. If fresh and contaminated water mix, it averages the contamination across the bodies, so when they separate they would then have half and half contamination. Same for salt levels, speaking of which...

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Time to hit the beach... for SCIENCE!

...

...Huh. Salt water is... strange. For one, when exposed to fresh water, salt water and fresh/murky water will refuse to overwrite the other. They actually WILL still share though! Seriously; although each tile remains static in whether it is 'Water' or 'Salt Water', they do appear to exchange units of liquid - effectively meaning that if you create a small hole next to the ocean, dump fresh water in there, then connect it to the open sea, you will have an infinite supply of purified water. No need for a screw pump.



Who the fuck needs Desalination plants!? Not dwarves, that's for damn sure. My guys were kicking back on the beach, drinking salt water filtered through nothing but a few drops of stagnant water

Which also seemed to spontaneously de-contaminate itself for some reason...



I also dealt with Aquifers at the beach. It seems like they fill adjacent tiles with the same system; open tiles fill with 3/4 units of fluid, so the aquifer rock is treated as a 7/7 tile that cannot be depleted. I connected an Aquifer-flooded tunnel up to salt water (pouring down the stairs) and interestingly enough, once the salt water touched regular water, it refused to 'claim' any more tiles as salt water. They were all signified as regular water.

I performed a repeat test to be sure, this time letting the salt water flow in before I triggered the aquifer. I'm sure Urist appreciated the gravity of his contribution to the field of dwarven water physics whilst he mined out an aquifer in an already-flooding room. The previous result seemed to be a fluke; salt water could claim tiles just as easily as regular water, it's just random to see if they 'jump' on a tile first. Also produced the same result: salt water and fresh water can exchange units, but cannot overwrite one another. Curious. My next thought would be to drain out regular and salt water tiles to see if they retained those values when fluids were removed - although that would take a lot of time and I feel like the answer is 'No'.


This is literally what it looks like.

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So... on closer inspection, water physics are even more fucked than I had anticipated. Some of this stuff might even be worth adding to the wiki, regarding how the liquids interact. I'd really love to see how salt and murky water interact with lava, but that's an elaborate thing to set up so I'll leave it be.

Now, to figure out if Fluid Bodies could solve these problems...

Isn't that just a more calculation-intensive variant of how it currently works (no flow rate, temp doesn't really spread more than 2 tiles away)?

It's a mess....But if you assume magma layer and instead calculate head towards the surface, that could greatly simplify things.

No idea, I'd have to research it some more.

Edited to talk about magma at the end there.

Heat aquifers? Haha, yeah, that would technically work.

EDIT: The way I see it, it'd run a number of loops at the start, until temperatures near magma seas and pockets stabilize. Although if magma was close enough to an underground cavern, it might run for a bit longer as it penetrates into underground air. After that, it really only calculates temperature changes that the player and other creatures create (dragonfire, dumping magma, etc). The heat system would be important if steam power is to work though.\

From the wiki:

Temperature transfer in DF is fairly simple - most temperature values have a whole part (in "degrees Urist") and a fraction part (which ranges from 0 to the material's SPEC_HEAT minus 1). Once per tick, the game calculates the relevant temperature difference (e.g. between the item itself and the tile in which it is located) and adds that to the fraction part, then adjusts the whole part until the fraction part is within range. For example, a piece of Lignite (which has SPEC_HEAT 409) at temperature 10015.0 (room temperature underground) exposed to Magma (temperature 12000) will heat up by 1985 fraction units, which will increase its temperature to 10019.349. In order to reach its ignition point of 11440, it would need to be in the magma for a total of 517 ticks, over 5 seconds at 100 fps.

That's pretty much what I described in terms of object and creature heat transfer, so that's all good. I still don't know how tile temperature transfer works though.

Non-residual magma pumpstack: design where every z-level(alternating empty space and floor) is
######
#+%% .#
######

#= wall

Since magma is placed and removed each step, it gives empirically around -1 FPS per z-level of it.

Residual means that instead of pumping to 1 floor tiles it pumps to 3, so that some magma will remain behind and not force temperature calculations for magma's removal, normalizing the temperature and making it skip the heat calculation. But if magma is always cooling, I'd think that might no longer matter.

What's worse, there would always be heat flowing upwards from magma sea and volcanoes - dissipating off the map edge could work, but it'd leave weird situations where center of embark is hotter than edges.

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I don't think heat affects pressure much with solids and liquids, since they don't expand/compress much with it. What it does affect is evaporation; air humidity isn't tracked right now.

Note that many specific heats are already in the raws, such as iron's 450.

For heat transfer, it probably should be most conductive - after all, current follows the most efficient path.

But if you have to check each individual tile for fluid sharing, it comes back to every-tile check. Ugh.

At which point might as well do local approximiation and either model everything in 1 tile as single heatsink, or give heat to everything in single tile at once. (It'd have the cool effect where dropping magma onto large enough pile of metal could have the metal cool down the magma to solidify it rather melt itself.)

In any case, don't see why heat flow has to be linked to fluids, rather than handled like fluids. Well, it is kinda same problem as whether handling new gaps for fluid bodies to flow into is efficient, expect whole map is an ocean.

...Much like the rest of the world, I hadn't actually considered the issue of global warming. Well, map-wide warming.

Again, I don't intend to track air either. Steam, maybe, so long as it's kept in a pressurized state (disappears/forms water without sufficient pressure, so it would delete itself if it escaped), but not really worrying about that right now.

Units to change; I'm just checking formulas and systems right now.

Yes, more conductive might be better.

If you want to measure Temp or Pressure adequately, doing an every-tile check is unfortunately unavoidable. I do have some ideas on how to alleviate the drain though.

I had only planned to consider temperature to convex between tiles - not creatures or objects. Those things can still be affected by heat, but they don't alter how it spreads. So if a ton of heat transferred into a tile containing a dorf, the dorf wouldn't affect how it spreads to the next tile, but it would change its temperature to match that of the heated tile. It could happen either instantly (spontaneous melting/freezing), or over a period of time (objects/creatures will adjust their temperature to match their tile at a certain rate, like 10 degrees a second). I like the latter since it allows you to escape danger, but it might be harder to program.

True, heat should probably be its own system.

Just water/magma, yeah, but if you want to define N new fluids, you'll need to write (N+2)! -2 interactions. And since just about anything in the game has liquid form, you'll likely want to define some rules instead, lest you die of old age first.

But then you have liquid rock + water = rock wall VS salt + water = salty water....And then checking for all this.

I'd suggest changing the magma to cool down into obsidian on its own, with water acting as just heatsink - but this probably would have massive FPS impact for each liquid body. (non-residual magma pumpstacks tend to lose -1 FPS per level of pumpstack)

I'm saying that, by default, liquids will have null interactions. You actually have to ADD effects if you want them to occur. Two liquids touching each other will have null reaction with each other unless there is a rule designating it. I suppose that still does mean you have to run a check of "Liquid A=X, I know X interacts with Y, is Liquid B=Y?" and so forth, so it isn't perfect. May need to workshop it.

Woah, I am NOT going that advanced. Water sitting next to a block of salt would not become salty in this system; there's no check for that. Not realistic, I know, but far easier. Rocks currently don't interact with adjacent rocks, after all. I just want a good flow system.

Fufu~ You'll enjoy my next post I was writing... (although I don't really understand what you mean by non-residual magma pumpstacks)

The myth generator screens actually seemed to leave room for that sort of thing, over on the right side it had adjectives like "lost" "doubted" "destroyed" and whatnot as I recall, I've got some of the shots I took from the video somewhere.

Is that the video of Tarn showing the prototype off? I had to stop watching because I was busy. Yeah, I'm pretty sure he mentioned somewhere that myths could become lost so that's a definite one, but I'm mainly concerned about the fact that he showed off a block of creation myth - feels like it'd imply there's only one creation myth per world, which is just not cricket.

It'd be great in Adventure mode to be faced with a bunch of different religions, each with codexes that contradict one another, making you unsure as to which is the truth, if any. Also that sense of suspicion if the god you worship even exists - or could just be asleep for a thousand years. It'd be Fun if you got fed up and renounced your god, only to be struck down for your impudence and disbelief. 

Maybe, if there was a Prime Myth that every other religion took bits of and added their own nonsense, you'd have the option to try and collate all the historical and religious information you can to decipher common Myths and Events. New Adventurer Job: Historian. It'd certainly give you a reason to visit libraries and collect books. Maybe you keep finding this mention of a Dark Tower in different cultures, so you venture out to it and see what information could be stored there.

EDIT: Watching the video now. It does seem to imply different cultures will interpret the creation myth differently (depending on what they were associated with), but they do seem to share gods. My question was about whether they'd believe entirely unique creation myths, but this might work better. I could see this as a Zeus/Jupiter situation, where they just call things differently but have a similar root, so that's very interesting and plays more into the historian idea. One issue I have is that it doesn't seem to generate unique religions - just race-wide ones. It'd be cool to see sects and offshoots from big religions that interpret the creation myth and its gods differently. Like if some necromancers believe one god was actually a death deity and rewrite history to fit their view.

EDIT2: Finished it. Now I feel silly, so I edited my question a bit. Basically I just want to know if we can expect lies to be possible.

This is pretty....Large idea, but honestly I have no idea if it would decrease the computational cost (PS: note that entity in DF refers to civilizations).

One problem with multiple liquids is their interaction, though this "multiple things existing in same space" problem is already present in how tossing things into fluids doesn't do more than give mist Chemical reactions are pretty complex, and this is why we have, say, molten cinnabar and molten chalk exist as objects, possibly in same magma pool, and not reacting or pushing magma out of it. To define an interaction for each of N fluids with each other, you'd need N! definitions, after all.

Bit of critique, though:

The ideas of miniscule and shared volume seems like it interacts weirdly with splitting up a murky pool to drying point and shared volume. Miniscule by itself means that N tile murky pool split into 7N+1 tile murky pool would totally dry out the moment water spread out fully, while 7N would instantly dry at the slightest evaporation but would last for a while, while 7N-1 would last for twice as long on average....You get the idea.

Though DF drying is not how actual drying works, so can lay it there.

Oh okay, didn't really know what to call it. Mobs maybe? Creatures? You could use the same system as those, but just give it a Null tile to exist in so it can't be interacted with. Instead it just operates through functions relating to various tile IDs that it 'owns'. I don't think it would use up too many resources doing checks, but pathfinding might be an issue. However even then you wouldn't be dealing with the hundreds or thousands of individual tiles like you do now. It'd deal with one Body each that knows which tiles it should fill with its combined volume. I'd probably avoid doing it every frame as well.

Hence why I'm against liquids actually having any interactions beyond affecting the Volume value of a tile, with higher density fluids taking priority for adjusting it. I feel like that's simple enough to work.

Yeah, I eventually decided that method of dealing with miniscule values wouldn't be feasible - basically for the reasons you've listed. Still don't really have a fix there, beyond bumping the units for volume far beyond the 7 we currently have.